The technique used to ensure security in virtual private networks (VPNs) is:

A. encapsulation.

B. wrapping.

C. transform.

D. encryption

Explanation:

Encapsulation, or tunneling, is a technique used to carry the traffic of one protocol over a network that does not support that protocol directly. The original packet is wrapped in another packet. The other choices are not security techniques specific to VPNs.